Alfred d yochet



(No Model.)

A. DYOGHET.

BXPANDING BLOCK. No. 497,854. Patented May 23,1893.

Uivrrnn 'rare PATENT Ormes.

ALFRED DYOOHET, OF PARIS, FRANCE, ASSIGNOR TO THE SOCIT ALSAOIENNE DESOONSTRUOTIONS MOANIQUES, OF BELFORT.

EXPANDING BLOCK.

SPECIFICATION forming part of Letters Patent No. 497,854,dated May 23,1893.

Application filed November 17, 1892. Serial No. 452,323. (No model.)

T0 all whom, t may concern:

Be it known that I, ALFRED DYocnnr, a citizen of France,and a residentof Paris,in the Departmentof the Seine,France, have invented a new anduseful Improvement in Expanding Blocks, of which the following is aspecification.

My invention relates to an improvement in that class of supportingblocks generally used in engineering shops for securing the work on thetables or plates of machine-tools. Solid wrought or cast iron linershave been heretofore employed for supporting the work, the height to befilled being completed with small iron or copper-plate wedges. Thissupporting process is very unsatisfactory while the strong pressure ofthe clamping dogs which secure the work to the table, causes these smallwedges, (on which the clamping dog bears merely by its edge,) to becollapsed, so that the finished and unclamped work has a curved ortwisted face, instead of a straight or true one. This inconvenience willbe absolutely avoided by employing, for the same purposes the expandingblock, which is the object of my invention,as it will behereinafter moresubstantially set forth.

In order that my said invention may be readily understood, I will nowproceed more particularly to describe the most convenient means, wherebythe same is to be carried out into practical effect, reference being hadto the accompanying drawings, in which- Figure l is an axiallongitudinal section of an expanding block designed according to myinvention. Fig. 2 is a transverse section of the same, upon line A B ofFig. l, and Fig. 3 an external view of the rear side ot' the block,showing the measuring or recording graduation.

My expanding block comprises two superposed metallic hollow wedges orinclines, l, 2, accurately fitted for sliding freely on each other. Thelower wedge 1 is provided with a longitudinally extending rib 3, thetransverse section of which is dove-tailed or T-shaped and which acts asa guide-way for the upper or sliding wedge 2, by its engagement with acorrespondingly shaped slot in the latter. The said rib is bored outwith a rectangular opening 4. in which works looselya counterbalancedratchet or catch 5 arranged for swinging loosely on or together with aremovable spindle 6. The nose of the ratchet 5 projects above the upperface of the rib 3, so, as to engage with a rack f7, the lower end 8 ofwhich is bent upwardly and serves as a nut for the adjusting screw g.This screw passes through and rotates freely in the end of the upperwedge, but is prevented from any longitudinal movement by means of ashoulder lO and collar ll locked on the screw-spindle.

The working of this device is as follows: Supposing that a long andiiexible work, such as a coupling bar for locomotive-wheels, is to besecured on the table of a grinding or milling machine. This coupling barrests upon its two heads, but the middle part thereof must be supportedin several points; otherwise it would sink under the pressure of theworking tool. In order to avoid this inconvenience, the hereinbeforedescribed expanding-block is set under the middle part of the bar. Theupper wedge is pushed upward and thus caused to slide upon the lowerwedge until it has been brought into contact with the under side of thework, the nose of the ratchet, during this movement, -j u mping over theteeth of the rack. Then by rotating the screw Q9 in the suitabledirection, the rack is drawn downward, until the tooth thereof, whichwas the closest to the nose of the f ratchet, has been brought to restupon it,

whereby the upper wedge is prevented from recoiling downward, theexpanded block acting then absolutely like a solid block of the sameheight. The graduation on the lower wedge and index on the upper oneenable the height of the block or relative position of the two wedges tobe measured and recorded with the utmost accuracy.

Having now described my invention, what l claim as new, and desire tosecure by Letters Patent, is-

1. An expanding block consisting of two superposed hollow wedges,connected together by means of a rib formed in one wedge with adovetailed or T-shaped transverse section and engaging a correspondinglyshaped slot in the other wedge, a counter balanced and IOO freelyrotating ratchet located in the lower wedge, a rack carried by andmovable independent ot' the upper wedge, engaging the nose of saidratchet and an adjusting screw, prevented from any longitudinal movementby a shoulder and collar locked thereon, for Working and controllingsaid rack, substantially as and for the purpose set forth.

2. An expanding block, consisting of two su- Io perposed wedges, aratchet or pawl carried by one wedge, a rack carried by and slidahleindependent of the other Wedge, and means for moving the rackindependent of any movement of the Wedge which carries the same,substantially as described.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

ALFRED DYOCHET.

Witnesses: v

W. JOUE, G. DELoNG.

